Preheat oven to 350 degrees. Coat a jumbo size muffin tin with nonstick cooking spray, or line with cupcake liners.
In a large bowl, cream butter and sugar until fluffy. Beat in the eggs and pumpkin puree.
In a separate bowl, whisk together the flour, salt, baking soda and spices.
Stir the dry ingredients into the wet ingredients until fully combined. Fold in 1 cup of the chocolate chunks.
Fill muffin tins 2/3 of the way with batter. Sprinkle evenly with coarse sugar. Bake 25-30 minutes, until a toothpick inserted in the center of a muffin comes out clean.
To make the chocolate drizzle, combine 1/2 cup of chocolate chunks and the coconut oil in a small bowl. Microwave in 20 second intervals until melted and smooth. Drizzle over cooled muffins.